The present invention relates to drilling with a downhole mud motor, and more particularly a mud motor designed to withstand higher torques and pressure operations.
Down-hole motors assemblies are well known in the drilling arts. Mud motors are one well-known type of down-hole motors. Mud motors are used to supplement drilling operations by turning fluid power into mechanical torque and applying this torque to a drill bit. The mud is used to cool and lubricate the drill bit, to carry away drilling debris and to provide a mud cake on the walls of the annulus to prevent the hole from sloughing in upon itself or from caving in all together. Mud motors operate under very high pressure and high torque operations and are known to fail in certain, predictable ways. The failure of a mud motor is very expensive, as the whole drill string must be pulled out of the bore hole in order to bring the mud motor to the surface where it can be repaired or replaced. This is a very time consuming and costly operation. Common problems that occur with prior art mud motors include; seal failure resulting in drilling mud in the universal joint in the transmission section; pressuring up, often called hydraulically locking, due to either fluid or gas being trapped within the confines of the tool itself, and broken bearing mandrels and resulting mud invasion into the bearings.
The primary aspect of the present invention is to provide a mud motor that will operate for longer periods with fewer failures.
Other aspects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.
A downhole mud motor assembly is disclosed which has an improved bearing mandrel and a bearing stop to transfer a larger percentage of the weight of the drill string to the bit. Also improved sealing systems for the transmission section and bearing section prevents drilling mud from entering critical components. A piston stop is provided to prevent the piston from damaging any parts as the piston moves under pressure. One or more compensating pressure disks are placed in the lower housing to prevent pressure from building up in the bearing section. A grooved ball seat is provided in the transmission to allow for greater flow of lubricant around the 1xc2xcxe2x80x3 balls.